Blood Res.  2015 Mar;50(1):19-25. 10.5045/br.2015.50.1.19.

Efficacy and safety of eltrombopag in adult refractory immune thrombocytopenia

• Kim YK
• Lee SS
• Jeong SH
• Ahn JS
• Yang DH
• Lee JJ
• Kim HJ

• KMID: 1787908
• DOI: http://doi.org/10.5045/br.2015.50.1.19

Abstract

BACKGROUND
Eltrombopag is a thrombopoietin receptor agonist with excellent treatment outcomes in immune thrombocytopenia (ITP). Here, we analyzed the dose of eltrombopag required to achieve and maintain safe platelet counts in Korean ITP patients.
METHODS
Adult refractory ITP patients (<30,000 platelets/microL) were enrolled. Eltrombopag doses were increased to achieve a target platelet count (> or =50,000 cells/microL). After achieving the target platelet count, the dose of concomitant ITP medications and eltrombopag was reduced to identify the lowest effective dose required to maintain the platelet count.
RESULTS
Among 18 patients, 66.7% achieved complete response, 5.6% achieved platelet counts between 50,000 and 100,000 cells/microL, and 27.8% failed to achieve the target platelet count. The median ITP duration was significantly shorter in patients who achieved the target platelet count. The initial dose required to achieve the target platelet count was 25 mg/d. The adjusted maintenance doses were 25 mg twice per week or 25 mg/d. After discontinuation, 83.3% relapsed, and the median relapse-free survival was 15 days. Two relapsed and 1 failed patient switched to romiplostim. The response to romiplostim was similar to eltrombopag. During eltrombopag treatment, 38.9% showed hepatobiliary laboratory anomalies. Among 9 follow-up bone marrow examinations, 1 revealed fibrosis after 1 year of treatment.
CONCLUSION
Eltrombopag was well tolerated with excellent treatment outcomes in refractory adult ITP patients. Low-dose eltrombopag effectively maintained the target platelet count. However, some patients required longer or higher-dose treatment to maintain the target platelet count, especially in heavily pretreated or longer ITP cases.

Keyword

Eltrombopag; Immune thrombocytopenic purpura; Platelets; Romiplostim

MeSH Terms

Adult*
Bone Marrow Examination
Fibrosis
Follow-Up Studies
Humans
Platelet Count
Purpura, Thrombocytopenic, Idiopathic
Receptors, Thrombopoietin
Thrombocytopenia*
Receptors, Thrombopoietin

Figure

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  Fig. 1 Summary of patient disposition in eltrombopag-treated patients (N=18). Among 5 patients who failed to achieve the target platelet count, 4 patients quit eltrombopag treatment and 1 increased the eltrombopag dosage. Among 13 patients who responded, 4 required the lowest dose of eltrombopag to maintain the target platelet counts and 9 quit eltrombopag treatment. Two of these 9 patients maintained CR, and 7 experienced a relapse. Two eltrombopag-resistant patients and 1 relapse patient were treated with romiplostim. Abbreviation: CR, complete response.

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